lol did you really not use periods. I ran out of breath while reading your original post lol.

just practice and you will get there. the car will tell you it needs a lower gear. i.e. you are going 50mph in 6th gear and you hit the brakes to slow down to 30mph. If,you leave it in 6th, the car will slighty shake, wont go anywhere really. thats when you know the car needs a lower gear to push itself forward. good luck and congrats.

 

Maybe I have my terminology wrong. I'm talking about the plate that's fixed to the transmission input shaft. If you're going down a hill, in gear but with clutch depressed, the rear wheels will be driving the transmission gears and input shaft. So, wheels and driveshaft will always have the same rpm at 65mph, but wouldn't a different transmission gear selection affect the input shaft's rpm (and anything that may be attached to that input shaft)?

 

OK, now I see your point, we started talking about 1st gear and yes the clutch plate would be going too fast. Putting the coasting gearbox into any other gear would slow down the clutch plate, yes.
I see that my previous comment 'in any gear' is misleading and can be taken two ways.
Coasting in gear is not very efficient if you want to save gas as there are friction losses in the gear box. Driving a gearbox from the opposite end gives mechanical losses that are even higher in the lower gears.